Ferrite

Download: Performance of Ferrite Magnets


Ferrite magnets are sintered permanent magnets composed of Barium or Strontium Ferrite. This class of magnets, aside from good resistance to demagnetization, has the popular advantage of low cost.

Ferrite magnets are very hard and brittle, and require specialized machining techniques. Moreover, they should be machined in an un-magnetized state. We are equipped to machine these materials to specifications.

Temperature Effects 

Up to about 840 F, changes in magnetization are largely reversible, while changes between 840 F and 1800 F are remagnetizable. For all Ferrite magnets, the degradation of magnetic properties is essentially linear with temperature. At 350 F, about 75% of room temperature magnetization is retained, and at 550 F, about 50% is retained.


Common Applications for Ferrite Magnets

Ferrite magnets are widely used in motors, magnetic couplings, for sensing, loudspeakers, holding-magnet systems, crafts, magnetic therapy, novelties, and toys.

Typical Magnetic Performance for Sintered Ferrite

1.Mostly Used national standard - SJ285-77 permanent ferrite magnet standard
2.Chinese standard -sj/T10410 2000 permanent ferrite magnet standard
3.USA standard - permanent ferrite magnet industry standard of USA
4.The standard from International Electronics Committee(IEC404-8-1)



Mostly Used national standard - SJ285-77 permanent ferrite magnet standard

Grade Value(min/typical in our factory)
Br Hcb(BHC) Hcj(IHC) (BH)max
MT KG KA/m Koe KA/m KOe Kj/m3 MGOe
Y10T(=C1) 200-218 2.00-2.18 125-145 1.57-1.82 210-250 2.64-3.14  6.5-8.0 0.8-1.0
Y25 360-370 3.60-3.70 135-150 1.70-1.88 140-170 1.76-2.14 22.5-25.3 2.8-3.2
Y30(=C5) 380-385 3.80-3.85 191-210 2.40-2.64 199-220 2.50-2.51 26.0-28.0 3.4-3.7
Y30BH 380-390 3.80-3.90 223-235 2.80-2.95 231-245 2.90-3.08 27.0-30.0 3.4-3.7
Y33 410-420 4.10-4.20 220-235 2.77-2.95 225-240 2.83-3.01 31.5-33.0 4.0-4.2
Y35 400-410 4.00-4.10 175-195 2.20-2.45 180-200 2.26-2.51 30.0-32.0 3.8-4.0
C8(=C8A) 385-390 3.85-3.90 235-255 2.95-3.20 242-265 3.05-3.33 27.8-30.0 3.5-3.7
C10 400-410 4.00-4.10 288-300 3.62-3.77 280-287 3.51-3.60 30.4-31.9 3.8-4.0


Chinese standard -sj/T10410 2000 permanent ferrite magnet standard

Material Br HcB HcJ (BH)max
mT KG KA/m Oe KA/m Oe Kj/m³ MGOe
Y8T 200-235 ≥2000 125-160 ≥1570 210-280 2610 6.5-9.5 ≥0.8
Y22H 310-360 ≥3100 220-250 ≥2770 280-320 3520 20.0-24.0 ≥2.5
Y25 360-400 ≥3600 135-170 ≥1700 140-200 1760 22.5-28.0 ≥2.8
Y26H-1 360-390 ≥3600 220-250 ≥2512 225-255 2830 23.0-28.0 ≥2.9
Y26H-2 360-380 ≥3600 263-288 ≥3300 318-350 4000 24.0-28.0 ≥3.0
Y27H 370-400 ≥3500 225-240 ≥2830 235-260 2950 25.0-29.0 ≥3.1
Y28 370-400 ≥3700 175-210 ≥2200 180-220 2260 26.0-30.0 ≥3.3
Y28H-1 380-400 ≥3800 240-260 ≥3020 250-280 3140 27.0-30.0 ≥3.1
Y28H-2 360-380 ≥3600 271-295 ≥3400 382-405 1800 26.0-30.0 ≥3.3
Y30 370-400 3.7~4.0 175-210 2.20~2.64 180-220 2.26~2.77 26.0-30.0 3.3~3.8
Y30H-1 380-400 ≥3800 230-275 ≥2890 235-290 2950 27.0-32.5 ≥3.4
Y30H-2 395-415 ≥3950 275-300 ≥3460 310-335 3900 27.0-32.0 ≥3.4
Y32 400-420 ≥4000 160-190 ≥2010 165-195 2070 30.0-33.5 ≥3.8
Y32H-1 400-420 ≥4000 190-230 ≥2390 230-250 2890 34.5-35.0 ≥4.0
Y32H-2 400-440 ≥4000 224-240 ≥2810 230-250 2890 31.0-34.0 ≥3.9
Y33 410-430 ≥4100 220-250 ≥2760 225-255 2830 31.5-35.0 ≥4.0
Y33H 410-430 ≥4100 250-270 ≥3140 250-275 3140 31.5-35.0 ≥4.0
Y34 420-440 ≥4200 200-230 ≥2510 205-235 2580 32.5-36.0 ≥4.1
Y35 430-450 ≥4300 215-239 ≥2700 217-242 2730 33.1-33.2 ≥4.2


USA standard - permanent ferrite magnet industry standard of USA

Material Br HcB HcJ (BH)max
mT KG KA/m KOe KA/e KOe kj/m³ MGOe
C1 230 2.30 148 1.860 258 3.50 8.36 1.05
C5 380 3.80 191 2.400 199 2.50 27.00 3.40
C7 340 3.40 258 3.230 318 4.00 21.90 2.75
C8(=C8A) 385 3.85 235 2.950 242 3.05 27.80 3.50
C8B 420 4.20 232 2.913 236 2.96 32.80 4.12
C9 380 3.80 280 3.516 320 4.01 26.40 3.32
C10 400 4.00 288 3.617 280 3.51 30.40 3.82
C11 430 4.30 200 2.512 204 2.56 34.40 4.32


The standard from International Electronics Committee(IEC404-8-1)

Grade Allowed Value (min/typical)
Br Hcb(BHC) Hcj(IHC) (BH)max
MT KG KA/m KOe KA/m KOe Kj/m³ MGOe
HF8/22 200-220 2.00-2.20 125-140 1.57-1.76 220-230 2.76-2.89 6.5-6.8 0.8-1.1
HF20/19 320-333 3.20-3.33 170-190 2.14-2.39 190-200 2.39-2.51 20.0-21.0 2.5-2.7
HF20/28 310-325 3.10-3.25 220-230 2.76-2.89 280-290 3.52-3.64 20.0-21.0 2.5-2.7
HF22/30 350-365 3.50-3.65 255-265 3.20-3.33 290-300 3.64-3.77 22.0-23.5 2.8-3.0
HF24/16 350-365 3.50-3.65 155-175 1.95-2.20 160-180 2.01-2.26 24.0-25.5 3.0-3.2
HF24/23 350-365 3.50-3.65 220-230 2.76-2.89 230-240 2.89-3.01 24.0-25.5 3.0-3.2
HF24/35 360-370 3.60-3.70 260-270 3.27-3.39 350-360 4.40-4.52 24.0-25.5 3.0-3.2
HF26/16 370-380 3.70-3.80 155-175 1.95-2.20 160-180 2.01-2.26 26.0-27.0 3.2-3.4
HF26/18 370-380 3.70-3.80 175-190 2.20-2.39 180-190 2.26-2.39 26.0-27.0 3.3-3.4
HF26/24 370-380 3.70-3.80 230-240 2.89-3.01 240-250 3.01-3.14 26.0-27.0 3.3-3.4
HF26/26 370-380 3.70-3.80 230-240 2.89-3.01 260-270 3.27-3.39 26.0-27.0 3.3-3.4
HF26/30 385-395 3.85-3.95 260-270 3.27-3.39 300-310 3.77-3.89 26.0-27.0 3.3-3.4
HF28/26 385-395 3.85-3.95 250-265 3.14-3.33 260-275 3.27-3.45 28.0-30.0 3.5-3.8
HF28/28 385-395 3.85-3.95 260-270 3.27-3.39 280-290 3.50-3.60 28.0-30.0 3.5-3.8
HF30/26 395-405 3.95-4.05 250-260 3.14-3.33 260-270 3.27-3.39 30.0-31.5 3.8-3.9
HF32/17 410-420 4.10-4.20 160-180 2.01-2.26 165-175 2.07-2.20 32.0-33.0 4.0-4.1
HF32/22 410-420 4.10-4.20 215-225 2.70-2.83 220-230 2.76-2.89 32.0-33.0 4.0-4.1
HF32/25 410-420 4.10-4.20 240-250 3.01-3.14 250-260 3.14-3.27 32.0-33.0 4.0-4.1